Negotiations for a massive Pacific trade deal will not sink plans for a new U.S. catfish safety inspection program despite protests that it may hurt an increasingly popular Vietnamese seafood import, U.S. officials told Reuters.

Vietnamese negotiators have raised objections to the planned U.S. Department of Agriculture (USDA) program in the 12-nation Trans-Pacific Partnership (TPP) trade talks, calling it a non-tariff trade barrier.

And U.S. catfish farmers have expressed concerns that the more rigorous inspection regime would be watered down during final negotiations. The plan, not yet finalized, would transfer catfish to the USDA from the Food and Drug Administration, which has safety responsibility for all other seafood.

But U.S. officials told Reuters that the catfish program would not be changed in the trade deal's food safety chapter, which is essentially completed and considered "stable text."

"The catfish statute is the law of the land. USDA is working toward a final rule, and TPP will not affect that," a U.S. official said on condition of anonymity because the overall trade deal is not yet finalized.

The final rules may require Hanoi to erect a parallel inspection program, similar to those USDA requires for countries exporting beef, pork and poultry to the United States. Vietnamese exporters say this could take years and in the interim, imports of Vietnam's pangasius catfish could be effectively barred.

Mississippi catfish farmer Bill Battle is shown in this still image taken from video as he discusses his industry's struggles with imports of pangasius catfish from Vietnam that have taken market share away from U.S. producers, at Battle Farms in Tunica, Mississippi, August 22, 2015.

The program's survival, at least for now, has given U.S. catfish growers hope that they can slow a rising tide of Vietnamese imports they claim are raised with antibiotics and chemicals banned in the United States to ward off disease, boost production and lower costs.

"Basically, the imports have taken about two thirds of our market," catfish farmer Bill Battle said recently as he showed a Reuters reporter hundreds of acres of former catfish pond beds that he has drained out of production at his farm in Tunica, Mississippi.

Catfish cousin

Pangasius, a cousin to the American channel catfish, has stormed U.S. supermarkets over the past decade, often marketed as swai or basa, and is now the sixth most-consumed seafood in America.

A Washington, D.C. Wal-Mart store recently sold a two-pound bag of frozen U.S. catfish fillets for $13.84, more than twice the price of the same size bag of swai fillets, with similar flavor and texture.

Pushed by lawmakers from the southern catfish farming states of Mississippi, Alabama, Arkansas and Louisiana, Congress first approved the USDA inspection program in 2008 as the industry was rapidly contracting and shedding thousands of jobs.

U.S. catfish production halved to 334 million pounds in 2013 compared to a decade earlier, while pond acreage fell by over 60 percent.

The industry has argued that the USDA would do more to ensure that catfish supplies are free of antibiotics, as the FDA has the capacity to inspect only about one percent of seafood imports.

A 2013 study by Dutch, Vietnamese and other international researchers found evidence of antibiotics use at all of the 32 pangasius farms they tested in Vietnam's Mekong Delta.

USDA program won't survive a challenge at the World Trade Organization if it goes ahead

"We just want a level playing field," Battle said. "We're not trying to keep the imports out. Bring 'em on. But they need to meet the same standards."

James Bacchus, a U.S. lawyer representing the Vietnam Association of Seafood Exporters and Producers, said the U.S. catfish farmers' allegations about pangasius are not based on science and the USDA program won't survive a challenge at the World Trade Organization if it goes ahead.

Bacchus, the WTO's former chief judge, said that the program would be "tantamount to an import ban" if it requires new inspection procedures that keep pangasius out of U.S. retailers' freezer cases. His clients are waiting for the final rules and "are ready to take legal action if and when it becomes necessary."

The new safety program also has been slammed by some Republican lawmakers as wasteful, duplicative and the same kind of food-safety trade barrier that the United States is trying to eliminate in other countries.

Senator John McCain, a Vietnam War veteran, in May called it "one of the most brazen and reckless protectionist programs that I have encountered in my time in the United States Senate."